The present invention relates to an exposure management system that performs management of exposure state of workers working in a radiation management region in a nuclear power plant, a nuclear fuel processing facility, or the like, and also to a dosimeter, and a wireless relay device.
A system in which a monitoring device communicates via a base station with a portable dosimeter having a telephone function such as a cellular phone or a PHS™, thereby collecting exposure dose data, is disclosed, for example in Japanese Patent Application Publication No. H11-248839 (referred to hereinbelow as “Document 1”), Japanese Patent Application Publication No. 2002-365366 (referred to hereinbelow as “Document 2”), and Japanese Patent Application Publication No. 2003-130956 (referred to hereinbelow as “Document 3”), as a radiation exposure management system for measuring the radiation dose in a radiation management region in a nuclear power plant or a nuclear fuel processing facility and conducting management in order to protect the workers from danger. Further, in a system described in Japanese Patent Application Publication No. 2004-12197 (referred to hereinbelow as “Document 4”) a primary station and a secondary station communicate by a specified low power radio station. The primary station and a monitoring device communicate by Ethernet™ via a wireless LAN. Exposure dose data are sent by wireless communication from the secondary station to the primary station, image data are sent by wired communication from a camera to the primary station, and the image and the exposure dose data are monitored at the same time. Further, Japanese Patent Application Publication No. 2003-14847 (referred to hereinbelow as “Document 5”) describes a system that uses wireless communication to collect exposure dose data and maps the exposure state.
In the case of a portable dosimeter that combines a cellular phone or PHS™ with a dosimeter, as described in Documents 1, 2, and 3, circuit connection is performed by dialing each time the monitoring device and the portable dosimeter communicate with each other. Therefore, it takes long time to be connected to the public line. As a result, such a system is not suitable for collecting information such as an exposure dose from all of the dosimeters in the facility quickly. Further, Documents 4 and 5 do not describe a feature of collecting a large number of dosimeter data quickly.
The present invention has been created to resolve the above-described problems intrinsic to conventional technology and provides an exposure management system, a dosimeter, and a wireless relay device that make it possible to collect exposure dose data from a large number of dosimeters quickly.